Early, intensive marine resource exploitation by Middle Stone Age humans at Ysterfontein 1 rockshelter, South Africa

Abstract

Modern human behavioral innovations from the Middle Stone Age (MSA) include the earliest indicators of full coastal adaptation evidenced by shell middens, yet many MSA middens remain poorly dated. We apply 230Th/U burial dating to ostrich eggshells (OES) from Ysterfontein 1 (YFT1, Western Cape, South Africa), a stratified MSA shell midden. 230Th/U burial ages of YFT1 OES are relatively precise (median ± 2.7%), consistent with other age constraints, and preserve stratigraphic principles. Bayesian age–depth modeling indicates YFT1 was deposited between 119.9 to 113.1 thousand years ago (ka) (95% CI of model ages), and the entire 3.8 m thick midden may have accumulated within ∼2,300 y. Stable carbon, nitrogen, and oxygen isotopes of OES indicate that during occupation the local environment was dominated by C3 vegetation and was initially significantly wetter than at present but became drier and cooler with time. Integrating archaeological evidence with OES 230Th/U ages and stable isotopes shows the following: 1) YFT1 is the oldest shell midden known, providing minimum constraints on full coastal adaptation by ∼120 ka; 2) despite rapid sea-level drop and other climatic changes during occupation, relative shellfish proportions and sizes remain similar, suggesting adaptive foraging along a changing coastline; 3) the YFT1 lithic technocomplex is similar to other west coast assemblages but distinct from potentially synchronous industries along the southern African coast, suggesting human populations were fragmented between seasonal rainfall zones; and 4) accumulation rates (up to 1.8 m/ka) are much higher than previously observed for dated, stratified MSA middens, implying more intense site occupation akin to Later Stone Age middens.

Microstructural and crystallographic evolution of palaeognath (Aves) eggshells

“…Palaeoenvironmental information can be acquired from eggshells (Stern et al, 1994; Montanari, 2018; Niespolo et al, 2020, 2021). Because Cenozoic palaeoenvironmental or geological events that might have influenced the evolution of Palaeognathae are comparatively well understood (Mitchell et al, 2014; Claramunt and Cracraft, 2015; Grealy et al, 2017; Yonezawa et al, 2017; Crouch and Clarke, 2019; Figure 13), further analytical investigation on Cenozoic palaeognath eggshells with proper geological and climatological contexts may shed light on the palaeoenvironmental settings of fossil localities and their effects in the evolution of Palaeognathae and its eggshells.…”

“…Palaeognath eggs were not only important food resource for hunter-gatherers (Oskam et al, 2011; Collins and Steele, 2017; Diehl et al, 2022) but were also used for cultural purposes such as ornaments or storage containers (Texier et al, 2010; Langley, 2018; Wilkins et al, 2021; Miller and Wang, 2022), thereby, they are common in archaeological sites. Because chronological and palaeoenvironmental information inscribed in palaeognath eggshells in archaeological sites are available through isotopic analyses (Sharp et al, 2019; Niespolo et al, 2020, 2021), detailed microstructural information for those eggshells may provide more colourful implications (e.g. identification, harvest timing of egg, and biostratigraphy) about the interactions between early human, specific palaeognath avifauna, palaeoenvironments, and the precise age of palaeognath eggshell materials (e.g.…”

Cost-Benefit Trade-Offs of Aquatic Resource Exploitation in the Context of Hominin Evolution

“…A decrease in limpet size associated to late Neanderthal exploitation has also been documented during the Upper Paleolithic (UP) in Europe, which may potentially be associated to increases in population growth and density during that period (Stiner et al, 1999). In addition, modeling research on cultural evolution shows that, through changing resource availability, technological development may result in further population growth (Kolodny et al, 2016), which in turn could expedite the reduction in the local availability of high-quality marine foods (Klein et al, 2004;Niespolo et al, 2021). In this context, a decrease in size and quality of marine stocks could cause a reduction in the yield, and consequently also in the benefit of foraging on local aquatic resources.…”

Ancient proteins resolve controversy over the identity ofGenyorniseggshell

“…In doing so, they were likely reproducing the same mode of interaction that they had established with another large, flightless bird: ostrich, albeit on other continents. Ostrich bones are rarely found in archaeological sites (66) but ostrich eggshell (OES) has been ubiquitous in human occupation sites in southern and eastern Africa since the Middle Stone age (20,(67)(68)(69). OES is also common in northern Africa, the Arabian peninsula, south western and northern Asia, as well as present-day India and China, throughout the Pleistocene and Holocene (70)(71)(72)(73)(74).…”

“…If this hypothesis is proven correct, it would imply that humans may have had an impact on the extinction of a volant, mound-building, relatively small (~5 kg) bird around 50 ka BP. People would thus have preferentially targeted eggs in hidden mounds and burrows, rather than collecting them from the ground nests of large flightless birds, the latter being a typical behaviour of modern humans, who had been exploiting ostrich eggs in Africa and Asia since at least 120 ka BP (20). More importantly, there would be no direct proof of human-Genyornis interaction, and it is indeed possible that Genyornis had already gone extinct by the time humans arrived in Australia.…”